Certification Problem
Input (TPDB TRS_Standard/SK90/2.03)
The rewrite relation of the following TRS is considered.
|
minus(minus(x)) |
→ |
x |
(1) |
|
minus(h(x)) |
→ |
h(minus(x)) |
(2) |
|
minus(f(x,y)) |
→ |
f(minus(y),minus(x)) |
(3) |
Property / Task
Prove or disprove termination.Answer / Result
Yes.Proof (by ttt2 @ termCOMP 2023)
1 Rule Removal
Using the
Knuth Bendix order with w0 = 1 and the following precedence and weight functions
| prec(f) |
= |
2 |
|
weight(f) |
= |
0 |
|
|
|
| prec(h) |
= |
0 |
|
weight(h) |
= |
2 |
|
|
|
| prec(minus) |
= |
3 |
|
weight(minus) |
= |
0 |
|
|
|
all of the following rules can be deleted.
|
minus(minus(x)) |
→ |
x |
(1) |
|
minus(h(x)) |
→ |
h(minus(x)) |
(2) |
|
minus(f(x,y)) |
→ |
f(minus(y),minus(x)) |
(3) |
1.1 R is empty
There are no rules in the TRS. Hence, it is terminating.